SB 7.11.5

śrī-nārada uvāca
natvā bhagavate ’jāya
 lokānāṁ dharma-setave
vakṣye sanātanaṁ dharmaṁ
 nārāyaṇa-mukhāc chrutam
Word for word: 
śrī-nāradaḥ uvāca — Śrī Nārada Muni said; natvā — offering my obeisances; bhagavate — unto the Supreme Personality of Godhead; ajāya — ever existing, never born; lokānām — throughout the entire universe; dharma-setave — who protects religious principles; vakṣye — I shall explain; sanātanam — eternal; dharmam — occupational duty; nārāyaṇa-mukhāt — from the mouth of Nārāyaṇa; śrutam — which I have heard.
Translation: 
Śrī Nārada Muni said: After first offering my obeisances unto Lord Kṛṣṇa, the protector of the religious principles of all living entities, let me explain the principles of the eternal religious system, of which I have heard from the mouth of Nārāyaṇa.
Purport: 

The word aja refers to Kṛṣṇa, who explains in Bhagavad-gītā (4.6), ajo ’pi sann avyayātmā: “I am ever existing, and thus I never take birth. There is no change in My existence.”